Bass Traps / Acoustic Panels 4" Thick 24"x 48" : Color Black : By Vibration Theory Installation is clean and easy as hanging a piece of art on a wall ( installation hardware attached - installation ready ) Smoother look than burlap for a design minded environment ( smooth and clean look, both from a distant and up close ) Made with fire resistant rigid 8 lbs density mineral rock wool with solid wood frames and backing Superior in effectiveness when compared with any other absorption material including any types of foam Receive instant shipping discounts when purchasing 2 or more